Material for matrices.



Unis

rarns Patented November 24, 1903.

PATENT i hi CEt MATERIAL. FOR MATRICES.

.BPEOIFIGATION formingpart of Letters Patent No. 744,889, dated November 24, 1903. Application filed June 8,1903. Serial No. 160,662. (No specimens.)

To-all whom it may concern:

Be it known thatLGILBERT JOHNSON WILD- RIDGE, managing director of Robert Craig and Sons, Limited, paper manufacturers, a subject of the King of Great Britain and Ireland, residing at Caldercruix Mills, Caldercruix, in the county of Lanark, Scotland,'have invented certain new and useful Improvements in Material for Matrices, of which the following is a specification.

This invention has for its object to produce improved materials to be used in making matrices for use, either Wet or dry, in casting for printing and other purposes and technically known as ilongs. Hitherto such materials or flongs have most generally been prepared by pasting togetheror otherwise building up by hand sheets of paper or a sheet or sheets of paper with other materials so as to constitute a matrix-making material or fiong.

The object of this invention is to make in a more eificent and economical manner than hitherto a matrix-making material or flong of an improved character and-consisting of a stiif backing, a bed or intermediate layer of a plastic character, and a face made as here inafter described, which flong will receive clear and sharp impressions from the type or the like without the material of the face of the matrix being broken by the type or the like or destroyed by the hot metal which is cast in the matrix, so that the matrix can be used for a number of castings, great saving in time in preparing the matrix for casting being effected bythe use of such fiong's.

. Accordingto my invention the face of the matrix-making material or flong(which face comes into contact with the type or the like in forming the matrix and with the hot metal in'casting) is made of a mixture of pulped material having pliable and tough fibers with a substance which is'resietant to the action of heat, and preferably also with a substance which will prevent the cast metal adhering to the face of the matrix and help to produce a glossy finish on the face of the matrix. It is preferred to use no size in making this face, and the fibrous material used should beso milled or treated in the pulper that the fibers are as pliable as possible. I'have found that flax is best suited for this purpose, that silicate of magnesia is suitable-for use as the heat-resisting substance, and that borax is suitable for use as the substance for preventing adherence of the casting to the face of the matrix and for helping to produce a glossy finish on the said face. the said face consists of one hundred parts, by weight,of flax, twenty-five parts, by weight, of silicate of magnesia, and three parts, by

weight, of borax; but I do not limit myself 'eral layers-namely, the face layer, the back layer, and the bed or intermediate layerare contained in separate vats, from which'the 7 several layers are produced, and these layers are brought together'at any suitable part of a paper-making machine while they are in a condition such that they adhere together and form a composite material of the character aforesaid. For example, one layer-say the layer for the face-may be brought to the combining place on an ordinary Fourdriniermachine Wire, while the other layers may each be formed by perforated or reticulated (wiregau'ze) cylinders rotating in the respective vats containing the pulps for making these I layers and be taken up successively by a felt, a

which conveys the layers of pulp to the part of the paper-making m aehine where they meet the layer from the machine-wire, so that this layer forms, say, one outer layer, the backing another outer layer, the bed or intermediate layer being between the said two outer layers, or the one layer-say the backingmay be formed on the wire of a Fourdrinier papermaking machine, and the other layer'ssay the intermediate. and face layers-may be formed on perforated or reticulated cylinders, or all the layers may be formed on perforated or reticulated cylinders, or these cylinders Ioo maybe dispensed with and all the layers be formed'upon a series of ordinary paper-mak lug-mach ne wires, such as are used in Fourdrinier paper-making machines. If desired,

A good mixture for i ing thebacking layer may be omitted and a backmaterial beapplied after the other two layers have been combined on the machine.

The combined layers are passed over a heatedmetal cylinder of large diameter and with a highly-polished periphery, the face layer being pressed against this periphery and reconstituent layersiof diate, layer,

niaining in contact therewith for a time long enou h to sufficiently dry the material, the hot periphety of the cylinderimparting to the face layer a smooth glazed finish, which is necessary for producing a smooth glossy face upon the type or the like on the castings takenfrom the, matrix.

Although {mention only three principal layers in this specification and in the claims, each princi'pal layer may of course be composed of two or more constituent layers, these layersbei'ng of the same character as each .other or somewhatvarying in character, provided that the main characteristics of the several principal layers be retained.

Having now particularly described and as- ."certained the nature of this invention and in each of the principal liong, consisting of the combination, with a backing layer, and a bed, or intermediate, layer, of pliable fibers and a substance, such as silicate of magnesia, which, is resistant to the action of heat, and of a substance, such as borax, which will prevent the adherence of the cast metal to the matrix, and help to pro- ;5 duce a glossy finish on the face.

3. A material, or' fiong, for making matrices for use incasting; the said material, or ilong, consisting of the combination, with a backing layer and a bed, or intermediate, layer, of a face layer composed of flax and silicate of magnesia.

4. A material, or llong, for making matrices for use in casting; the said material, or i'long, consisting of the combination, with a backing layer and a bed, or intermediate, layer, of a face layer, composed of flax and silicate of magnesia and borax.

5. A material, or i'long, for making matrices for use in casting; the said material, or fiong," having a face layer composed of, or containing, pliable fibers, and silicateof mag-- nesia.

(J. A material, or flongjfor making matrices for use in casting; the said material, or flong, having a face layer composed of, or containing, pliable fibers, silicate of magnesia and borax.

In testimony whereof I affix my signature in presence of two witnesses.

, Witnesses:

GEORGE Conn, ROBERT FINDL Y Soo'r'r.

of a face layer consisting of a mixture 4o 

